[Feature] pin_message tool — allow bot to pin messages in groups

[Rustam-Z]

Problem

The bot can send, edit, and delete messages but has no way to pin them. This is useful for:

• Pinning weekly digest posts so they're visible at the top of the group
• Pinning important announcements or reminders
• Any recurring content the operator wants persistent visibility for

Currently a group admin has to pin messages manually after the bot posts them.

Proposed solution

Add a pin_message(chat_id, message_id) MCP tool:

pin_message(chat_id: int, message_id: int, disable_notification: bool = True) -> None

Calls Telegram's pinChatMessage API. Requires the bot to have admin rights with the "Pin Messages" permission in the target group.

Also consider a matching unpin_message(chat_id, message_id) and unpin_all_messages(chat_id) for completeness.

Use case that prompted this

Weekly trend-digest posts fired via a recurring reminder — the bot posts the digest but can't pin it. An admin currently has to pin it manually each Monday.

Notes

• Bot needs to be promoted to admin with pin permission in each group where this is used
• disable_notification=True default avoids spamming users with a "message was pinned" notification on every digest
• Should be listed in --allowedTools like other messaging tools
• Low risk — pinning is reversible

Requested by

Muhammadjon (group member), approved by Rustam (owner).